Triacetoxyperiodinane → t-butyl (1R)-1-(4-(2-methylpentyloxy)phenyl)-2-oxoethylcarbamate

Participants

Reaction Steps

A solution of t-butyl (1R)-2-hydroxy-1-(4-(2-methylpentyloxy)phenyl)ethylcarbamate (500 mg, 1.48 mmol) prepared according to the procedure described in example 1, in dichloromethane (10 mL) was treated with sodium bicarbonate (622 mg, 7.41 mmol) and Dess-Martin Periodinane (1.26 g, 2.96 mmol) at room temperature. The mixture was stirred at room temperature under N2 for 1.5 h. The reaction mixture was placed in an ice-water bath and a 1:1 mixture of saturated aqueous NaHCO3 solution and saturated NaHSO3 solution (4 mL) was added and the cooling bath was removed and the mixture was stirred for 5 min at room temperature. The reaction mixture was transferred to a separatory funnel containing saturated aqueous NaHCO3 solution (20 mL). The aqueous layer was extracted with ethyl acetate (3×25 mL). The combined organic layers were washed with brine (20 mL), dried over MgSO4, filtered and concentrated. The residue was purified by column chromatography on silica gel (10%→15% ethyl acetate in hexanes, 25 g column) to afford t-butyl (1R)-1-(4-(2-methylpentyloxy)phenyl)-2-oxoethylcarbamate (318 mg, 64% yield) as a colorless oil which was stored in the freezer until used in the next step: 1H NMR (400 MHz, DMSO-d6) δ 9.48 (s, 1H), 7.76 (d, J=7.6 Hz, 1H), 7.23 (d, J=8.6 Hz, 2H), 6.93 (d, J=8.6 Hz, 2H), 5.11 (d, J=7.6 Hz, 1H), 3.82 (dd, J=9.6, 6.0 Hz, 1H), 3.73 (dd, J=9.3, 6.5 Hz, 1H), 1.82-1.92 (m, 1H), 1.40 (s, 9H), 1.25-1.49 (m, 3H), 1.11-1.22 (m, 1H), 0.96 (d, J=6.8 Hz, 3H), 0.88 (t, J=7.1 Hz, 3H); LRMS (ESI) m/e 279.2 [(M-t-Bu)+, calcd for C15H21NO4 279.1].

Provenance & Evidence